Combined vacuum circuit breaker and current transformer device

ABSTRACT

One or more vacuum circuit breakers are mounted inside a horizontally disposed hollow skirted porcelain insulator tube having sealed ends. The insulator tube extends through and is supported by current transformer means which have the shape of an annular torus. The current transformer means is supported on a framework which is grounded to the current transformer means. Circuit breaker operating means, including an electrically insulating rod, extend between the circuit breaker or breakers and the lowe portion of the framework.

United States Patent Milwaukee. Wis.

[54 I COMBINED VACUUM CIRCUIT BREAKER AND CURRENT TRANSFORMER DEVICE 2 Claims, 2 Drawing Figs.

s2 u.s.ci 200/144, 317/15, 336/174 [51] lnl.Cl r .1. H01h9/56 [50] Field of Search o. ZOO/144.2, 148', 317/15, 58; 336/174, 175; l74/C.T.Digest [56] References Cited UNITED STATES PATENTS 1,301,636 4/1919 Arnold 336/175 2,925,570 2/1960 Strock 336/ l 75X 3,082,389 3/1963 Settles ct a1 336/174 2,859,309 1 1/1958 Schwageret a1 ZOO/144(2) 3,114,815 12/1963 Easley et al.... ZOO/148(1) 3,123,698 3/1964 Waterton ZOO/144(2) 3,311,726 3/1967 Fish,.lr. .1 200/l48(.1)

Primary ExamincrRobcrt S. Macon Allomeyx-Thumas F. Kirby, Robert B. Benson and Lee H.

Kaiser ABSTRACT: One or more vacuum circuit breakers are mounted inside a horizontally disposed hollow skirted porcelain insulator tube having sealed ends. The insulator tube extends through and is supported by current transformer means which have the shape of an annular torus, The current transformer means is supported on a framework which is grounded to the current transformer means. Circuit breaker operating means, including an electrically insulating rod, extend between the circuit breaker or breakers and the lower portion of the framework.

COMBINED VACUUM CIRCUIT BREAKER AND CURRENT TRANSFORMER DEVICE SUMMARY OF THE INVENTION One type of high voltage outdoor vacuum circuit interrupted device comprises a metal cabinet into which a pair of insulator bushings extend and a vacuum circuit breaker is mounted between the ends of the bushings within the cabinet. Operating mechanism for the circuit breaker is mounted within the cabinet. Necessary current transformers are connected to the line outside of the cabinet as a separate installation. Vacuum circuit interrupter devices of the foregoing type are relatively bulky and, because of the requirement to provide a separate current transformer, are also costly.

OBJECT OF THE INVENTION It is an object of this invention to provide a combined vacuum circuit breaker and current transformer device which is more compact and less costly than equivalent prior art apparatus.

Another object is to provide a device of the aforesaid character wherein one or more circuit breakers are mounted inside a hollow insulator tube, wherein the tube is surrounded and supported by current transformer means and wherein the current transformer means are mounted on a support which has an operating means connected to the breakers.

Other objects and advantages of the invention will hereinafter appear.

DESCRIPTION OF THE DRAWING The accompanying drawing illustrates two preferred embodiments of the invention but it is to be understood that the embodiments illustrated are susceptible of modifications with respect to details thereof without departing from the scope of the appended claims.

In the drawing:

FIG. 1 is a cross-sectional view of a combined vacuum circuit breaker and current transformer device in accordance with the invention; and

FIG. 2 is a view similar to FIG. 1 showing a device incorporating two series connected vacuum circuit breakers.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1 the numeral designates one embodiment of a combined vacuum circuit and current transformer device in accordance with the present invention. It is to be understood that device 10 is to be used in one of the phase lines of a high voltage multiphase electrical power transmission system and that similar devices would be used in the other phase lines.

Device 10 comprises a horizontally disposed hollow skirted insulator tube 12 in which a vacuum circuit breaker 14 is mounted. Tube 12 is supported by current transformer means 16 which are shaped like an annular torus and which are supported by a framework or support 18 having a base 20. Operating means 22 for circuit breaker 14 are connected between the circuit breaker and base 20.

Insulator tube 12 is preferably made of porcelain or other insulating material and has a configuration which enables it to withstand voltages on the order of 34,000 volts and higher. Insulator tube 12 is provided with a relatively heavy unskirted center section 24 for extra strength and this section is provided with a plurality of grooves 26 which aid in securely mounting current transformer means 16 thereon. Insulator tube 12 is provided with end caps 28 and 30 which seal oh the end of the tube and are held in place by a plurality of tie rods 32 which extend through the tube and are made of suitable insulating material.

End cap 28 on tube 12 supports an electrical connector 34 which is electrically connected by a conductor 36 to a stationary contact rod 38 on vacuum circuit breaker 14.

End cap 30 on tube 12 rigidly supports vacuum circuit breaker 14, as by means of volts 40, within tube 12 and also supports an insulated housing 42 for operating means 22. A movable contact rod 44 on vacuum circuit breaker I4 is electrically connected by a conductor 46 to an electrical connector 48 on housing 42.

Current transformer means 16 comprises an exterior protective cover or shell 50, preferably metallic, which is rigidly mounted on support 18 and filled with a solidified electrically insulating potting compound 52. Potting compound 52 fills the grooves 26 in insulator tube 12 thereby preventing axial slippage of the current transformer means I6 on the tube. A current transfomier 54 comprising a laminated magnetizable core 56 and a secondary winding 58 is embedded in the potting compound 52. Secondary winding 58 of current transformer 54 is provided with wire connection leads 60 and 62 which extend downwardly to base 20, preferably through a conduit 64 which is part of support 18. Secondary winding 58 of current transformer 54 surrounds conductor 36 and is therefore responsive to current flow through the latter to produce an output signal through the leads 60 and 62 which. as will be understood, is usable to effect operation of operating means 22 in any customary manner.

Operating means 22 comprise a linkage 66 which is connected to reciprocably movable contact rod 44 and is pivotable to open and closed positions about a pivot point 68 by reciprocably movable operating rod 70 made of insulating material. If preferred, rod 70 may be housed in a tube 72 connected between base 20 and housing 42.

As will be apparent in the foregoing construction, the current transformer which is at ground potential is fully insulated from the high potential being carried by the vacuum circuit breaker l4 and other associated components. Similarly, the components of operating means 22 which are at high potential (i.e., those associated with movable contact 44 of vacuum circuit breaker 14) are insulated from base 20 by insulated rod 70, insulated housing 42 and insulated tube 72.

Referring to FIG. 2, the numeral designates a combined device incorporating another embodiment of the invention wherein insulator tube 12 contains within it two series connected vacuum circuit breakers 82 and 84 which are understood to be similar to breaker 14, hereinbefore described. Breaker 82 is supported by end cap 30 and breaker 84 is supported by means of a flange or ring 86 which is entrapped between the adjacent ends of a pair of insulating tubular spacers or liners 88 and 90 which fit within insulator tube 12. The spacers 88 and 90 are compressed between the end caps 28 and 30 of insulator tube 12. Operating means 92 are provided to effect simultaneous opening and closing of both vacuum circuit breakers 82 and 84 and comprises a linkage 94 for association with a movable contact rod 96 on circuit breaker 82 and a linkage 97, comprising an insulating rod 98, for association with a movable contact rod 100 on a circuit breaker 84. Movable contact rod 100 of circuit breaker 84 is electrically connected to a stationary contact rod I02 on circuit breaker 82 by a conductor 104. Current transformer assembly 16 of combined circuit breaker and current transformer device 80 surrounds a portion of conductor 104 and movable contact rod 100 to monitor current flow and device 80 is suitably connected in an energized circuit.

lclaim: 1. An electrical device comprising: an insulator tube; first and second end caps on said tube for closing the ends thereof; 5

at least one insulating tie rod for securing said end caps in place and extending through said tube; 1

at least one vacuum-type circuit breaker disposed within said tube in a high potential region and supported by said first end cap;

said circuit breaker having contact rods extending therefrom and at least one of said rods being movable to effect circuit breaker operation;

an insulated housing mounted on said first end cap;

a first linkage for said movable contact rod located within said housing in said high potential region;

a first electrical connector mounted on said housing;

a first electrical conductor connected between said first connector and said one contact rod;

a second electrical connector mounted on said second end cap;

a second electrical conductor connected between said second connector and the other of said contact rods of said first circuit breaker;

current transformer means comprising a core and coil I potted in electrical insulating material which maintains them at ground potential;

said current transformer means surrounding and supporting said insulator tube;

' supporting means including a base at ground potential for a movable electrically insulating rod connected between said operating linkage and said base. 2. An electrical device according to claim 1 comprising a second vacuum-type circuit breaker disposed within said tube in said high potential region and having contact rods extending therefrom, at least one of which rods being movable, to effect operation of said second circuit breaker;

a pair of spacers of insulating material in said tube compressed between said end caps;

a supporting ring of insulating material entrapped between said spacers for supporting said second circuit breaker;

a second linkage disposed within said tube for operating said movable contact rod of said second circuit breaker;

a movable insulating rod connected between said first and second linkages;

wherein said second electrical conductor is connected between said second connector and the other of said contact rods of said second circuit breaker; and

further comprising a third electrical conductor connected between said other contact rod of said one circuit breaker and said one contact rod of said second circuit breaker. 

1. An electrical device comprising: an insulator tube; first and second end caps on said tube for closing the ends thereof; at least one insulating tie rod for securing said end caps in place and extending through said tube; at least one vacuum-type circuit breaker disposed within said tube in a high potential region and supported by said first end cap; said circuit breaker having contact rods extending therefrom and at least one of said rods being movable to effect circuit breaker operation; an insulated housing mounted on said first end cap; a first linkage for said movable contact rod located within said housing in said high potential region; a first electrical connector mounted on said housing; a first electrical conductor connected between said first connector and said one contact rod; a second electrical connector mounted on said second end cap; a second electrical conductor connected between said second connector and the other of said contact rods of said first circuit breaker; current transformer means comprising a core and coil potted in electrical insulating material which maintains them at ground potential; said current transformer means surrounding and supporting said insulator tube; supporting means including a base at ground potential for supporting said current transformer means; wire leads connected between said current transformer coil and said base; and a movable electrically insulating rod connected between said operating linkage and said base.
 2. An electrical device according to claim 1 comprising a second vacuum-type circuit breaker disposed within said tube in said high potential region and having contact rods extending therefrom, at least one of which rods being movable, to effect operation of said second circuit breaker; a pair of spacers of insulating material in said tube compressed between said end caps; a supporting ring of insulating material entrapped between said spacers for supporting said second circuit breaker; a second linkage disposed within said tube for operating said movable contact rod of said second circuit breaker; a movable insulating rod connected between said first and second linkages; wherein said second electrical conductor is connected between said second connector and the other of said contact rods of said second circuit breaker; and further comprising a third electrical conductor connected between said other contact rod of said one circuit breaker and said one contact rod of said second circuit breaker. 